connectors-ci: skipped status when metadata upload exits with 5

[alafanechere]

What

#28767 changed how we identify steps as skipped.
The exit code that leads to the "skipped" step status is now defined at the Step subclass level and is not global.
It introduced a regression for the MetadataUpload step - when its container exits with 5 it means the upload was skipped because the metadata yaml already exists on the bucket.

How

Declare in MetadataUpload that the skipped exit code is 5

[evantahler]

5

[evantahler]

I don't really understand why 5...

[alafanechere]

@evantahler when we implemented the metadata service upload we made its process exit with 5 when the upload was skipped because the file hash is the same on the bucket. 0 when the upload is successful, 1 one it failed.
It just a way for this process run inside a container to tell airbyte-ci that the upload was skipped. We picked 5 because pytest exists with the same status code when all tests are skipped.